[BACKGROUND OF THE INVENTION]
Field of the Invention
-
The present invention relates to a cement-based
joint body having excellent antifouling activity, such
as excellent antimicrobial activity, fungicidal activity
or antialgal activity, and a joint filler for said joint
body.
Background Art
-
A cement-based joint filler which is used for
filling a gap (the so-called "joint portion") provided
between tiles generally contains portland cement as a
binder and an aggregate, such as silica sand or calcium
carbonate. This cement-based joint filler is hardened
with hydration of the portland cement to form a cement-based
joint body. Although this joint portion is
desirably clean after formed, the joint portion is
soiled with the elapse of time. The cause of this is
mainly considered as follows. A large volume of pores
formed during hardening remains within the joint body,
and various inclusions are likely to be deposited in the
pores. In particular, when the inclusions are organic
matter, it may be a nutrient for fungi and pathogenic
bacteria derived from the air and, thus, they are likely
to grow. Further, in the case of use in an outdoor
environment, algae are also likely to grow. The joint
portion should be therefore frequently cleaned to keep
the joint portion clean.
-
Under these circumstances, several proposals have
been made on cement-based materials having excellent
antimicrobial activity and fungicidal activity or
treatment method thereof.
-
Japanese Patent Laid-Open No. 321600/1994 describes
a fungicidal agent-containing cement-based material.
-
Japanese Patent Laid-Open No. 158418/1999 describes
a method for the fungicidal treatment of a tile joint,
wherein a fungicidal treating agent comprising an
aqueous penetrable waterproof agent, prepared by aqueous
emulsification of a water-repellent alkylalkoxysilane,
and a fungicidal agent incorporated therein is coated on
a tile joint after hardening.
-
Japanese Patent Laid-Open No. 36157/1998 describes
a technique wherein a cement admixture comprising a
specific organosilicon component and an emulsifier
having an HLB value of 20 to 30 is used to maintain
water repellency and waterproof properties for a long
period of time and consequently to enhance endurance
properties.
[SUMMARY OF THE INVENTION]
-
The present inventors have now found that, in a
cement-based joint body comprising an
antimicrobial/fungicidal agent and/or a photocatalytic
metal oxide, soiling of the joint portion can be
effectively prevented by regulating the particle
diameter of the aggregate and the water absorption after
hardening. The present invention has been made based on
such finding.
-
Accordingly, it is an object of the present
invention to provide a cement-based joint body, which
has excellent antifouling activity, such as
antimicrobial, fungicidal, or antialgal activity and, in
addition, can maintain the antifouling activity for a
long period of time, and a joint filler for the cement-based
joint body.
-
According to one aspect of the present invention,
there is provided a cement-based joint body comprising a
hydraulic material, a particulate aggregate having a
particle diameter of not more than 10 µm, and an
antimicrobial/fungicidal agent and/or a photocatalytic
metal oxide, wherein said cement-based joint body has a
water absorption of not more than 10%.
-
According to another aspect of the present
invention, there is provided a cement-based joint filler
for the production of said joint body, comprising a
hydraulic material, a particulate aggregate having a
particle diameter of not more than 10 µm, and an
antimicrobial/fungicidal agent and/or a photocatalytic
metal oxide, and having a water absorption, after
hardening, of not more than 10%.
[BRIEF DESCRIPTION OF THE DRAWING]
-
Fig. 1 is a diagram showing a test on resistance to
fungi of the joint body according to the present
invention, wherein (a) shows the state of the joint body
before cultivation of test fungi and (b) the state of
the joint body after cultivation of test fungi. In the
drawing, numeral 1 designates a joint body, numeral 2 an
agar medium, numeral 3 an aseptic portion (inhibited
zone), and numeral 4 a fungi propagated portion.
[DETAILED DESCRIPTION OF THE INVENTION]
Definition
-
In the present invention, the term "joint body"
means a hardened product which has been filled into
between plates of plate building materials, such as
tiles, large earthenware plates, or stone materials, and
is exposed on the surface thereof. The term "joint
filler" means a material, before hardening, which fills
a gap between plates of plate building materials, such
as tiles, large earthenware plates, or stone materials,
to form a joint body.
-
In the present invention, the term "water
absorption" refers to a value determined by a method
wherein a joint body after hardening is satisfactorily
dried (for example, for 48 hr), the dried joint body is
immersed in water, and, when the water absorption is
substantially saturated (for example, after 48 hr),
calculation is made according to the following equation:
Water absorption (%) = (W1 - W0)/W0 x 100
wherein W0: mass before immersion, g, and W1: mass after
immersion, g.
-
The water absorption is preferably measured
according to JIS A 6203 (1996). This JIS, together with
English translation thereof, is easily available from
Japanese Industrial Standards (1-24, Akasaka 4-chome,
Minato-ku Tokyo, Japan). Further, the method is
described in detail in the working examples below.
Cement-based joint body and joint filler for
cement-based joint body
-
The cement-based joint body according to the
present invention comprises a hydraulic material, a
particulate aggregate having a particle diameter of not
more than 10 µm, and an antimicrobial/fungicidal agent
and/or a photocatalytic metal oxide. Further, according
to the present invention, the water absorption of the
joint body is brought to a very low value such as not
more than 10%.
-
The antifouling activity of the joint body
according to the present invention is attainable from
the following functions.
- a) The deposition and adsorption of bacteria, fungi,
and algae per se on a portion within the joint body can
be prevented.
- b) The absorption of organic soil in water, which
serves as a nutrient for bacteria, fungi, and algae,
into the joint body can be prevented.
- c) The component with antifouling activity is
gradually eluted from the joint body by water, and this
permits the antifouling activity for a long period of
time.
-
-
That is, according to the present invention, the
functions a) to c) are synergistically exhibited to
provide an effect such that the antifouling activity,
such as antimicrobial activity, fungicidal activity, or
antialgal activity, is excellent and, at the same time,
this antifouling activity can persist for a long period
of time.
-
According to a preferred embodiment of the present
invention, the water absorption of the joint body is not
more than 5%, more preferably 1.7 to 5%, most preferably
1.7 to 3%. When the water absorption is in this range,
the functions a) to c) become more significant,
contributing to further improved antifouling activity.
-
According to the present invention, the low water
absorption is mainly realized by adding a particulate
aggregate having a particle diameter of not more than 10
µm to the hydraulic material to densify the structure.
Further, according to a preferred embodiment of the
present invention, lower water absorption can be easily
ensured by adding the above particulate aggregate and,
in addition, a water repellent to the hydraulic material.
-
The components of the joint body according to the
present invention will be described. These components as
such are identical to the components of the joint filler
according to the present invention.
(a) Hydraulic material
-
The hydraulic material used in the present
invention includes those commonly used as a cement-based
powder. Examples of preferred hydraulic materials
include portland cement, such as normal portland cement,
and other various types of cement, such as alumina
cement, fly ash cement, and silica cement.
-
According to a preferred embodiment of the present
invention, the total amount of the hydraulic material is
not less than 20% by weight, more preferably 30 to 50%
by weight, based on the whole cement-based joint filler,
from the viewpoint of maintaining the strength of the
joint base material.
(b) Aggregate
-
Particulate aggregates having a particle diameter
of not more than 10 µm, that is, particulate aggregates
without particles having a size exceeding 10 µm, are
used as the aggregate according to the present invention.
The incorporation of the particulate aggregate can
enhance the filling level of the joint body to improve
the denseness of the joint body structure and thus to
lower the water absorption of the joint body. It is
considered that, by virtue of the low water absorption
which can be realized in this way, the functions a) to
c) are synergistically exhibited and the excellent
antifouling activity can be exhibited for a long period
of time.
-
The particulate aggregate according to the present
invention is not particularly limited so far as the
particle diameter of the aggregate is not more than 10
µm. Examples of preferred particulate aggregates include
various aggregates, such as silica stone powder,
aluminum hydroxide, silica powder, calcium carbonate,
volcanic ash, silica fume, mica, diatomaceous earth, and
synthetic resin powder.
-
According to a preferred embodiment of the present
invention, the particle diameter of the particulate
aggregate is not more than 5 µm. This can further
improve the denseness of the joint body and can further
lower the water absorption, whereby the antifouling
activity can be further improved.
-
According to a preferred embodiment of the present
invention, the total amount of the particulate aggregate
is 1 to 70% by weight, more preferably 5 to 40% by
weight.
-
According to a preferred embodiment of the present
invention, the cement-based joint filler according to
the present invention may further contain a coarse
aggregate having a particle diameter of not less than 10
µm. This can prevent, for example, cracking of the joint
caused by shrinkage on drying and thus can
advantageously ensure the strength of the joint. Coarse
aggregates commonly incorporated into joint fillers may
be used as the coarse aggregate without particular
limitation. Examples of coarse aggregates include silica
sand, aluminum hydroxide, calcium carbonate, volcanic
ash, silica fume, mica, and diatomaceous earth.
-
According to a more preferred embodiment of the
present invention, the content of the coarse aggregate
is not more than 60% by weight, still more preferably
about 10 to 40% by weight, based on the whole cement-based
joint filler.
(c) Antimicrobial/fungicidal agent
-
The antimicrobial/fungicidal agent includes those
generally called "antimicrobial agents" or "fungicidal
agents." Examples of preferred antimicrobial/fungicidal
agents include tepconazole, zinc 2-pyridinethiol-1-oxide,
2,4,4'-trichloro-2'-hydroxydiphenyl ether, and 10,10'-oxybisphenoxyarsine.
Among them, tepconazole and zinc 2-pyridinethiol-1-oxide
are more preferred. The combined
use of two or more of them is also preferred.
-
According to a preferred embodiment of the present
invention, the total content of the antimicrobial/
fungicidal agent is large enough to impart antifouling
activity, such as antimicrobial activity, fungicidal
activity, or antialgal activity, to the joint body.
Specifically, the total content of the antimicrobial/
fungicidal agent is preferably about 0.01 to 5.0% by
weight, more preferably about 0.1 to 1.0% by weight,
based on the whole cement-based joint filler.
(d) Photocatalytic metal oxide
-
Examples of preferred photocatalytic metal oxides
include titanium oxide, zinc oxide, and tin oxide. Among
them, titanium oxide is preferred because titanium oxide
is highly photocatalytically active, inexpensive, and
easily available. More preferred are, for example,
powders and sols of TiO2 having an anatase crystal
structure. In particular, fine powders are more
preferred from the viewpoints of improved specific
surface area and increased probability of the presence
of the photocatalyst on the surface of the joint.
-
According to a more preferred embodiment of the
present invention, the photocatalytic titanium oxide has,
supported thereon, ions of at least one metal
(preferably 0.01 to 10% by weight) selected from the
group consisting of copper, silver, zinc, platinum, iron,
and nickel. This can further enhance the antifouling
activity. For example, the photocatalytic titanium oxide
with the metal supported thereon may be produced as
follows. An aqueous solution containing metal ions, such
as copper, silver, zinc, platinum, iron, or nickel ions,
is first added to the photocatalytic titanium oxide
powder and/or sol. The application of light from an
ultraviolet lamp to this aqueous solution causes a
photoreduction reaction of metal ions to fix the metal
onto the surface of the photocatalytic titanium oxide.
Thus, photocatalytic titanium oxide with a metal
supported thereon is prepared.
-
According to a preferred embodiment of the present
invention, the amount of the photocatalytic titanium
oxide is large enough to impart antifouling activity,
such as antimicrobial activity, fungicidal activity, or
antialgal activity, to the joint body. More specifically,
the amount of the photocatalytic titanium oxide is
preferably about 0.01 to 10.0% by weight, more
preferably about 0.1 to 5.0% by weight, based on the
whole cement-based joint filler. When the amount of the
photocatalytic titanium oxide is in this range, the
antifouling effect can be satisfactorily developed by
the photocatalyst without lowering, for example, water
absorption and hardening speed of the joint.
(e) Water repellent
-
According to a preferred embodiment of the present
invention, the joint body may further contain a water
repellent. When this water repellent is used in
combination with the particulate aggregate, the water
absorption of the joint body can be further lowered. As
a result, higher antifouling activity can be exhibited
for a long period of time. Examples of preferred water
repellents include fatty acids; fatty acid salts, such
as, calcium salts of fatty acids, magnesium salts of
fatty acids, barium salts of fatty acids, sodium salts
of fatty acids, potassium salts of fatty acids, and
lithium salts of fatty acids; paraffin emulsions;
asphalt emulsions; resin emulsions; rubber latexes;
water-soluble resins; siliceous compounds; zirconium
compounds; and organic silicic acids. Among them, fatty
acid salts and paraffin emulsions are more preferred.
-
According to a preferred embodiment of the present
invention, the total amount of the water repellent is
about 0.01 to 10.0% by weight, more preferably about 0.3
to 3.0% by weight, based on the whole cement-based joint
filler.
(f) Alkali metal silicate
-
According to a preferred embodiment of the present
invention, the joint body may further contain an alkali
metal silicate. This embodiment can prevent
efflorescence of the joint body, while making it
difficult for contaminants to be deposited onto the
surface of the joint. Thus, better appearance of the
joint body can be maintained. Examples of preferred
alkali metal silicates include sodium silicate,
potassium silicate, lithium silicate, and mixtures
thereof.
-
According to a more preferred embodiment of the
present invention, the amount, based on 100 parts by
weight of the cement powder, of the alkali metal
silicate incorporated is 1 to 300 parts by weight in the
case of powder and 10 to 500 parts by weight in the case
of the aqueous solution, still more preferably 5 to 50
parts by weight in the case of the powder and 10 to 200
parts by weight in the case of the aqueous solution.
(g) Additive
-
According to a preferred embodiment of the present
invention, if necessary, the cement-based joint body may
contain various additives used in conventional cement
joints. Examples of such additives include admixtures,
waterproofing agents, pigments, water retaining agents,
and hardening control agents (hardening accelerators and
hardening retarders).
-
According to a preferred embodiment of the present
invention, the content of the additive is not more than
10% by weight, more preferably about 1.0 to 3.0% by
weight, based on the whole cement-based joint filler.
Production process of joint filler and joint body
-
The joint filler according to the present invention
can be produced by properly mixing the above-described
various starting materials. In this case, the amount of
the particulate aggregate added and the amount of the
water repellent added are properly determined so that
the water absorption of the joint body after the
hardening of the joint is brought to not more than 10%.
-
The joint filler according to the present invention
thus obtained, when applied, is kneaded with water, and
the kneaded product is then filled into gaps between
plates of tiles or the like. The filled joint filler is
cured and hardened to produce the joint body according
to the present invention. Although curing conditions are
not particularly limited, curing under conditions of
temperature 5 to 35°C and humidity 50 to 90% for 2 to 7
days are preferred.
-
According to another embodiment of the present
invention, the production process comprises applying the
same joint filler as described just above except for
freedom from the antifouling component and/or the water
repellent and, in such a wet state that curing of the
joint filler has not been completed, coating the
antifouling component and/or the water repellent onto
the outermost surface of the joint.
[EXAMPLES]
-
The present invention will be described in more
detail with reference to the following examples, though
it is not limited to these examples only.
Examples A1 to A3
(a) Preparation of joint fillers
-
For each of Examples A1 to A3, starting materials
were mixed together at mixing ratio specified in Table 1.
Thus, joint fillers were prepared.
(b) Measurement of water absorption
-
The water absorption was measured according to JIS
A 6203 (1996) as follows. Water was added to the joint
filler prepared in step (a), followed by kneading to a
slump value of 35 ± 5 mm as measured according to JIS A
1173. The kneaded product was molded to form a molded
product having a size of 40 mm x 40 mm x 160 mm. After
molding, the molded product was allowed to stand under
conditions of temperature 20 ± 2°C and humidity not less
than 80% for 48 hr and was then removed from the mold,
followed by curing in water having a temperature of 20 ±
2°C for 5 days and then curing under conditions of
temperature 20 ± 2°C and humidity (60 ± 10)% for 21 days.
Thus, three joint bodies were prepared. The joint bodies
were dried at a temperature of 80 ± 2°C for 48 hr and
were then cooled within a desiccator, and the mass of
these joint bodies was measured. Next, the joint bodies
were immersed in clear water having a temperature of 20 ±
2°C, and, after the elapse of 48 hr from the initiation
of the immersion, were taken out of the clear water.
Each side of these joint bodies was then quickly wiped
with a wet cloth, and, immediately after that, the mass
of the joint bodies was measured. The water absorption
was calculated according to the following equation, and
the values for the three joint bodies were averaged. The
results are shown in Table 2.
WA = (W1 - W0)/W0 x 100
wherein WA: water absorption, %, W0: mass after drying, g,
and W1: mass after absorption of water, g.
(c) Evaluation of antimicrobial/fungicidal activity
-
Water was added to each joint filler prepared in
step (a), and the mixtures were kneaded to a substantial
hardness level of an ear lobe. The kneaded products were
molded into molded products having a size of 2.5 cm x
2.5 cm square and a thickness of 2 mm. After molding,
the molded products were cured under conditions of
temperature 20°C and humidity 65% for 14 days. Thus,
joint bodies 1 were prepared. For the joint bodies 1,
the antimicrobial/fungicidal activities were evaluated
before running water treatment (initial stage) and after
running water treatment.
(i) Initial antimicrobial/fungicidal activities
-
For the joint bodies 1 thus obtained, the initial
antimicrobial/fungicidal activities were evaluated as
follows. At the outset, these joint bodies 1 were stored
in a carbon dioxide incubator for 148 hr, and were
adjusted to pH 7.0 to 8.9. Next, as shown in Fig. 1(a),
the joint bodies 1 after pH adjustment were placed at
the center of a petri dish with a diameter of 90 mm, and
an agar medium 2 containing 25 ml of potato dextrose was
added to the Schale and solidified. Next, 0.1 ml of a
spore suspension for each test bacterium or fungus
specified in Table 2 (1.0 x 106/ml) was coated on the
solidified agar medium 2, followed by cultivation at 28°C
for 7 days.
-
The state of the joint bodies after the cultivation
for 7 days within the petri dish is schematically shown
in Fig. 1(b). As shown in Fig. 1(b), the propagation of
fungi was not observed in the joint body 1 and the
aseptic portion (inhibited zone) 3 around the joint body
1 in the agar medium 2. On the other hand, a fungi
propagated portion 4 was observed in the agar medium 2
in its portion other than the joint body 1 and the
aseptic portion (inhibited zone) 3. For each test piece
and each test bacterium or fungus, the aseptic portion
(inhibited zone) 3 and the fungi propagated portion 4
were visually inspected, and the inhibition level of
growth of the strain in the joint body 1 was evaluated
according to the following criteria (four grades): "+++"
not grown, "++" inhibited zone observed, "+" grown to
the peripheral portion of the test piece, and "-" grown
also on the test piece. The results are shown in Table 2.
(ii) Antimicrobial/fungicidal activities after running
water treatment
-
To evaluate the antimicrobial/fungicidal activities
after running water treatment, the joint bodies 1 after
the pH adjustment were allowed to stand under running
water (water temperature 43°C) at a flow rate of 16
ml/min·cm2 for 1500 hr to accelerate the elution of the
antimicrobial/fungicidal agent, and were then taken out
of the running water. For the joint bodies 1 after the
running water treatment, in the same manner as in the
test i), the cultivation of each test bacterium and each
test fungus was carried out to evaluate the propagation
of the bacteria and fungi.
Comparative Examples A1 and A2
-
The preparation of joint bodies, the measurement of
water absorption, and the evaluation of antimicrobial
activity/fungicidal activity were carried out in the
same manner as in Examples A1 to A3, except that, as
specified in Table 1, the particulate aggregate and the
water repellent were not used in the mixing. The results
are shown in Table 2.
| | Ex. A1 | Ex. A2 | Ex. A3 | Comp. Ex. A1 | Comp. Ex. A2 |
| Mixing ratio |
| Portland cement | 50 | 50 | 50 | 50 | 50 |
| Silica stone powder (size: not more than 5 µm) | 10 | 10 | 10 |
| Silica sand No. 7 | 20 | 20 | 20 | 20 | 20 |
| Calcium carbonate | 17.3 | 17.3 | 17.8 | 27.8 | 28.3 |
| Water retaining agent | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 |
| Admixture | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| Tepconazole | 0.5 | 0.5 | 0.5 | 0.5 | - |
| Zinc 2-pyridinethiol-1-oxide | 0.5 | 0.5 | - | 0.5 |
| Thiopentazole | - | - | - | - | 0.5 |
| Paraffin emulsion | 0.5 | - | - | - | - |
| Calcium stearate | - | 0.5 | 0.5 | - | - |
| Total | 100 | 100 | 100 | 100 | 100 |
| | Ex. A1 | Ex. A2 | Ex. A3 | Comp. Ex. A1 | Comp. Ex. A2 |
| Water absorption, % | 4.7 | 4.4 | 4.8 | 22.6 | 23.0 |
| Initial antimicrobial/fungicidal activities |
| Fungicidal activity |
| Cladosporium TOF-91 | +++ | +++ | ++ | +++ | + |
| Phoma TOF-162 | +++ | +++ | ++ | +++ | - |
| Alternaria TOF-46 | ++ | ++ | ++ | ++ | + |
| Aureobasidium TOF-677 | +++ | +++ | ++ | +++ | + |
| Ulocladium TOF-150 | +++ | +++ | ++ | +++ | + |
| Penicillium TOF-686 | +++ | +++ | ++ | +++ | + |
| Aspergillus TOF-558 | +++ | +++ | ++ | +++ | + |
| Trichoderma TOF-155 | ++ | ++ | + | ++ | - |
| Antimicrobial activity |
| P. aeruginosa IFO-13736 | +++ | +++ | + | +++ | - |
| E. coli IFO-15034 | +++ | +++ | + | +++ | - |
| S. aureus IFO-13276 | +++ | +++ | + | +++ | - |
| Antimicrobial/fungicidal activities after running water treatment |
| Fungicidal activity |
| Cladosporium TOF-91 | ++ | ++ | + | - | - |
| Phoma TOF-162 | + | ++ | + | - | - |
| Alternaria TOF-46 | + | ++ | + | - | - |
| Aureobasidium TOF-677 | + | ++ | + | - | - |
| Ulocladium TOF-150 | ++ | ++ | + | - | - |
| Penicillium TOF-686 | ++ | ++ | + | - | - |
| Aspergillus TOF-558 | ++ | ++ | + | - | - |
| Trichoderma TOF-155 | + | + | + | - | - |
| Antimicrobial activity |
| P. aeruginosa IFO-13736 | + | + | - | | - |
| E. coli IFO-15034 | + | ++ | + | - | - |
| S. aureus IFO-13276 | + | + | - | - | - |
Examples B1 to B4
(a) Preparation of joint fillers
-
For each of Examples B1 to B4, starting materials
were mixed together at mixing ratio specified in Table 3.
Thus, joint fillers were prepared.
(b) Measurement of water absorption
-
The preparation of joint bodies and the measurement
of the water absorption were carried out in the same
manner as in Examples A1 to A3, except that the joint
fillers prepared in step (a) described just above were
used. The results are shown in Table 4.
(c) Evaluation of antialgal activity
-
Water was added to each joint filler prepared in
step (a), and the mixtures were kneaded to a substantial
hardness level of an ear lobe. The kneaded products were
molded into molded products having a size of 5 cm x 5 cm
square and a thickness of 10 mm. After molding, the
molded products were cured under conditions of
temperature 20°C and humidity 65% for 14 days. Thus,
joint bodies 1 were prepared. The joint bodies thus
obtained were immersed in a water tank (COD = about 100
ppm), wherein water does not run, disposed outdoors for
15 days to propagate algae on the joint bodies. After
immersion for 15 days, the test pieces were lightly
shaken under the water to evaluate the level of easiness
of the separation of algae. Further, the weight of algae
remaining deposited onto the test pieces after the light
shaking within the water tank was measured.
Comparative Example B1
-
The preparation of joint bodies, the measurement of
water absorption, and the evaluation of antialgal
activity were carried out in the same manner as in
Examples B1 to B4, except that, as specified in Table 3,
the particulate aggregate and the water repellent were
not used in the mixing.
| | Ex. B1 | Ex. B2 | Ex. B3 | Ex. B4 | Comp. Ex. B1 |
| Mixing ratio |
| Portland cement | 50 | 50 | 50 | 50 | 50 |
| Silica stone powder (size: not more than 5 µm) | 10 | 10 | 10 | 10 |
| Silica sand No. 7 | 20 | 20 | 20 | 20 | 20 |
| Calcium carbonate | 17.3 | 17.3 | 17.3 | 17.3 | 28.8 |
| Water retaining agent | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 |
| Admixture | 1 | 1 | 1 | 1 | 1 |
| Calcium stearate | 0.5 | 0.5 | 0.5 | 0.5 |
| Photocatalytic titanium oxide | 1 | 2 | 5 | 5 |
| Tepconazole | | | | 0.5 |
| Total | 101 | 102 | 105 | 105.5 | 100 |
| Water absorption, % | 4.3 | 4.4 | 4.6 | 4.6 | 23.0 |
Results
-
After immersion for 15 days, upon light shaking of
the test pieces in water, the algae deposited on the
joint bodies prepared in Examples B1 to B4 were removed,
whereas algae grown on the joint test piece prepared in
Comparative Example B1 could not be removed.
-
The weight of algae remaining deposited even after
light shaking of the test piece within the water tank is
shown in Table 4.
| | Ex. B1 | Ex. B2 | Ex. B3 | Ex. B4 | Comp. Ex. B1 |
| Weight of algae, g/25 cm2 | 0.2 | 0.13 | 0.04 | 0.03 | 1.38 |
Example C1
(a) Preparation of joint fillers
-
Starting materials were mixed together at the
following mixing ratio to prepare a joint filler.
Mixing ratio:
-
| Portland cement |
50 |
| Silica stone powder |
10 |
